Labiatae herb extracts and hop extracts for extending the color life and inhibiting the growth of microorganisms in fresh meat, fish and poultry

ABSTRACT

Compositions comprising a Labiatae herb extract and a hop extract containing beta acids and methods of using them to extend the color life and retard the growth of microorganisms in fresh meat, fish and poultry stored in an atmosphere that contains 20% or more oxygen.

FIELD OF THE INVENTION

[0001] This invention relates to compositions and methods for extendingthe shelf life of fresh meat, fish and poultry.

BACKGROUND OF THE INVENTION

[0002] Meat manufacturers are looking for ways to enable them to supplyretail outlets from efficient, cost effective, central-processingcenters. Increased shelf life with regard to both color (consumeracceptance) and spoilage (consumer safety) is required to make thispossible as meat makes its way through longer distribution channels fromproducer to retailer to consumer.

[0003] Color shelf life is important to consumer acceptance. Consumersjudge the freshness of meat by the presence of bright red oxymyoglobinpigment. Oxymyoglobin in fresh meat decreases with time during storageas it changes to the stable brown pigment, metmyoglobin. Althoughoxymyoglobin pigment fades during dark storage, for example in a meatlocker, pigment loss is most pronounced in lighted, refrigerated displaycases in retail establishments. Although pigment loss is primarilycosmetic in nature, it has serious economic consequences. Consumers insearch of the freshest looking cuts avoid purchasing meat containingeven small amounts of brown metmyoglobin. The unsaleable product whichresults from oxymyoglobin loss in red meats costs the industry anestimated $700 million dollars annually.

[0004] Shelf life associated with microbial spoilage is a more seriousissue. The potential liability associated with food born illnessoutbreaks from the sale of microbially contaminated meat is enormous.The meat industry and associated retail outlets are seeking ways toinsure consumer safety by preventing microbial contamination all alongthe manufacturing process. Process improvements such as carcass washingand carefully controlled low temperature processing are now routine inthe industry. Modified atmosphere packaging (MAP) of meat products hasalso improved microbial shelf life of fresh meat products. Someprocessors have begun treating meat with ionizing radiation to extendthe microbial shelf life of meat products. The irradiation process is aneffective method for controlling microorganisms on meat, but manyconsumers are wary of its use. There is a need in the industry forantimicrobial methods and processes which are perceived by consumers asbeing more natural. The invention described below addresses this demandusing GRAS (generally regarded as safe) seasonings.

[0005] Centrally processed meat will encounter at least two distinctstorage environments prior to sale to a consumer. It will be stored inthe dark at approximately 4° C. soon after production and duringdistribution. Prior to sale, it is likely to be stored in arefrigerated, illuminated display case. The general problem of enhancingthe shelf life of fresh meat, then, can be separated into threesubcategories: preserving the color during dark storage, preserving thecolor during storage in the lighted display case, and preventing thegrowth of spoilage organisms and pathogens throughout the commerciallydesirable storage period. We have discovered that treating meat with acombination of Labiatae herb extracts and hop extracts containing betaacids provides a novel method for enhancing the color shelf life underboth dark and light storage conditions and for suppressing the growth ofmicroorganisms for a commercially desirable period. The Labiatae herbextracts have been found to round out and suppress the bitter flavor ofthe hop extracts and allow for surprisingly high and truly effectiveconcentrations of hop extracts to be added to meat without a negativeflavor impact. The composition of this invention, a combination of hopextracts, Labiatae herb extracts and a storage atmosphere containingoxygen has been found to inhibit the growth of Gram positivemicroorganisms and very surprisingly, even Gram negative microorganisms.Prior art teaches that hop extracts do not control Gram-negativeorganisms. The hop and rosemary extracts are synergistic in theireffects.

[0006] The antimicrobial activity of hop extracts and compounds againstGram-positive bacteria has been known for a long time. Hop extracts havenot been considered effective against Gram-negative organisms. Theantimicrobial activity of hop compounds has been studied mostly ingrowth media. Minimum inhibitory concentrations (MIC) have beendetermined in these media. For beta acids, the MIC is around 1 ppm. Whentested in food, however, the MIC levels rise dramatically. The primaryinfluences on MIC being fat content (the higher the fat content, theless antimicrobially active the hop acid). Another factor is pH (thelower the pH, the more active the hop acid). MICs for skim and 2% milkhave been reported at 100 ppm. This rises to 1000 ppm in whole milk. TheMillis et al patent teaches that beta acid flavor is noticeable at 15ppm and becomes objectionable at 50 ppm. When hop acids are used athigher levels, the bitter flavor imparted to the food becomes asignificant limiting problem. The main prior art is summarized below:

[0007] M. Teuber and A. F. Schmalreck (Arch. Mikrobiol. 94 (1973) pp.159-171) review the use of hop extracts in medicine and reiterate thatgram-negative microorganisms are generally not affected by hop extracts.Minimum inhibitory concentrations effective for Gram-positive organismswere determined for: Lupulone (beta acids)  1 g/ml (1 ppm) humulone  2g/ml (2 ppm) isohumulone  25 g/ml (25 ppm) humulinic acid 250 g/ml (250ppm)

[0008] W. J. Simpson and J. R. M. Hammond, (Antibacterial Action of HopResin Materials, EBC Congress, 1991, Chapter 21, pp. 185-192) describethe mode of action of trans-isohumulone (an isoalpha acid) andcolupulone (a beta acid) against beer spoilage organisms. They indicatethat low pH favors the antibacterial activity of isohumulone. Therelative activity dropping from 226 at pH 3.8 to 42 at pH 4.6. They alsodemonstrate that colupulone has an effect on intracellular pH ofrecombinant lactic acid bacteria containing lux genes from the marineorganism Vibrio fischeri. By implication, colupulone had antibacterialactivity against this Gram-positive lactobacillus.

[0009] A. E. Larson, et al. (Antimicrobial Activity of Hop ExtractsAgainst Listeria monocytogenes in Media and in Food, Int. J. FoodMicrobiol. 33 (1996) pp. 195-207) describe the effect of hop extractscontaining varying amounts of humulones (alpha acids) and lupulones(beta acids) on controlling Listeria, a Gram-positive microorganism, inmedia and in certain foods. A hop extract (II) consisting of 41% betaacids, 12% alpha acids, and the remainder a mixture of desoxy-alphaacids, hop oils and hop waxes was found to be inhibitory at aconcentration of 0.1 mg/ml (100 ppm) in skim and 2% milk and 1 mg/ml(1000 ppm) in whole milk and was listericidal in low fat cottage cheeseat a concentration of between, 100 and 3000 ppm. A hop extract (III)consisting of 29.7% colupulone, 65% lupulone plus adlupulone, 8%desoxy-alpha acids, 7% water and 0.6% isoalpha acids enhanced the rateof inactivation of Listeria in coleslaw at a concentration of 1 mg/g(1000 ppm). Extract (III) showed no inhibitory effect even at 10,000 ppmin full fat camembert cheese. Both extracts (II) and (III) wereinhibitory in trypticase soy broth cultures at the 0.01 mg/liter (0.01ppm) level. This prior art teaches that inhibitory effects exhibited byhop extracts in media grossly over exaggerate the effectiveness of thehop extract in an actual food matrix. For example, the differencebetween 0.01 ppm in broth and 1000 ppm in coleslaw is a factor of100,000. They conclude that because something works in culture mediadoes not indicate it will work in food systems. Food systems requiremuch higher concentrations of hop acids to show an antimicrobial effectthan would have been predicted by the simple culture tests. This paperalso teaches that “Overall, the antimicrobial activity of hop extractsappears to increase with acidity and lower fat content. Our resultsindicate that hop extracts could be used to control L. monocytogenes inminimally processed food with low fat content.”

[0010] E. A. Johnson and G. J. Haas (UK Patent Application GB 2,330,076,publication date Apr. 14, 1999) teaches that hop extracts are usefulantibacterial agents against Clostridium botulinum and Clostridiumdifficile, both Gram positive organisms. They state that concentrationsof 1 ppm or greater beta acids or hop extracts inhibit the growth ofthese organisms. Their examples are in the form of lab cultureexperiments in growth media. They surmise that hop extracts can beconveniently incorporated into food products to prevent disease causedby these microorganisms. This teaching is counter to the teaching by thesame authors (A. E. Larson et al.) cited above which advises thatextrapolations from culture media experiments to complex foods are notstraightforward.

[0011] Millis et al. (U.S. Pat. No. 5,206,586) claims the use of betaacids for inhibiting Listeria in packaged foods, at a concentration of6-50 ppm. Examples show culture only, not extension to food systems.Millis et al. claims there are serious flavor limitations to the use ofbeta and states that beta is noticeable at 15 ppm and objectionableabove 50 ppm. Millis et al.'s claims on inhibition of Listeria inpackaged foods are not supported by examples, but based upon hisdemonstrations of inhibition in broth. The Larson et al. prior art citedabove shows that such a sweeping generalization is not supportable.

[0012] Barney et al., U.S. Pat. No. 5,455,038, teaches thattetrahydroisohumulone and hexahydrocolupulone are superior to Millis etal.'s beta acids for inhibiting Listeria in cultures.Tetrahydroisohumulone inhibited Listeria in soy broth at a concentrationof between 6-18 ppm. Under the same conditions, hexahydrocoluluponeinhibited Listeria at 0.4 ppm.

[0013] Barney et al., U.S. Pat. No. 5,370,863 teaches thattetrahydroisohumulone can inhibit Gram-positive bacteria that causeperiodontal disease.

[0014] Maye, et al., PCT Application WO 00/52212 teaches that the acidform of the hop acid is superior to the salt form in inhibiting bacteriain an aqueous process stream. All hop acids appear to be covered.

[0015] Johnson and Haas, Japanese Patent Application 11-221064 teach theuse of spraying foods or drinks with a solution (preferably an ethanolsolution) with a hop extract or the ingredients of a hop extract in aconcentration of >1 ppm and preferably at least 5 ppm, preferablyfurther containing beta acid, preferably in the presence of a surfactantsuch as tween 80.

[0016] Rhodia Corporation has introduced a line of spray-dried solidscontaining hop ingredients added to control Gram positive organisms.They are extensions of a product line which use propionobacteriacultures as a natural source of propionates, which are well knownantimicrobial compounds effective against Gram-negative organisms.Microgard® MG 225 consists of a dextrose based culture and a natural hopflavor. This product is especially effective against cold lovingGram-negative bacteria, certain yeasts and molds and selectGram-positive bacteria. Microgard® 325 consists of a skim milk basedculture and natural hop flavor. It is reportedly active againstGram-positive organisms in low fat, low protein foods.

[0017] W. J. Simpson and A. R. W. Smith (J. Appl. Bacteriol. 72, (1992),pp. 327-334) showed that antibacterial activity increases withdecreasing pH and that lipid material interferes with the activity oftrans-isohumulone against Lactobacillus brevis, a Gram positiveorganism.

[0018] G. J. Haas and R. Barsoumian (J. Food Protect. 57, (1994) pp.59-61) examined isoalpha acids and beta acids against a variety ofmicroorganisms and looked at resistance development. Minimum inhibitoryconcentrations of isoalpha acids were in the 0.01 to 0.03% (100-300 ppm)in tryptic soy broth. MIC for beta acids were 0.003-0.01% (30-100 ppm)in the same media against a variety of Gram-positive Staphylococcusorganisms. E. coli B, a Gram negative, was not sensitive to either ofthe hop resins.

[0019] J. S. Hough et al., (Brew. Ind. Res. Found. 63, (1957) pp.331-333) provide another example of effectiveness against Gram positiveorganisms and ineffectiveness against Gram negative (Acetobactersuboxydans). MIC for lupulone=1-10 ppm in culture.

[0020] J. L. Shimwell (J. Inst. Brew. 43, (1937) 191-195) provides yetanother example of activity against Gram positive and inactivity or evenstimulating effects against Gram negative.

[0021] The antimicrobial activity of Labiatae herbs has also been thesubject of study. Most prior art indicates that the antimicrobialactivity of the herbs is centered in the volatile essential oilcomponents.

[0022] P. M. Davidson and A. S. Naidu (in Natural Food AntimicrobialSystems, A. S. Naidu, ed., 2000, CRC Press, Boca Raton, pp. 265-294)review the antimicrobial properties of phyto-phenolic compounds fromessential oils of spices, herbs, edible grains and seeds. The authorsteach that the antimicrobial effects of spices and herbs are primarilydue to the presence of phenolic compounds in the essential oil fractionsand that some terpenes seem to show some activity, as well. Carvacrol,p-cymene and thymol are identified as the major volatile components oforegano, thyme and savory that likely account for the observed activity.The active antimicrobial agents of rosemary have been suggested to beborneol, camphor, 1,8-cineole, alpha pinene, camphene, verbenone andbornyl acetate. The active constituent of sage has been suggested to bethujone. Minimum lethal concentrations of essential oils of thyme oilhave been shown to range from 225-900 ppm in cultures. Theseconcentrations of essential oils in foods would cause serious flavorproblems. Since culture experiments underestimate the concentrationnecessary for effectiveness in foods, the flavor problems in foods arelikely to be more serious than even the culture numbers suggest. Inanother portion of this reference, minimum inhibitory concentrations ofessential oils were stated as 1-2% for rosemary, 0.12-2% for thyme,0.12-2% for spearmint, 0.5-2% for sage, 0.5-2% for peppermint and0.12-2% for oregano. In the summary, the authors state thatconcentrations of antimicrobial compounds in herbs and spices are toolow to be used effectively without adverse effects on the sensorycharacteristics of a food.

[0023] Y. Kimura et al., U.S. Pat. No. 4,380,506, teach a process forproducing a preservative having antioxidant and antimicrobial activity.Their process involves partitioning an extract of herb spices betweenpolar and non-polar solvents. Some of the partitioned extracts showedantimicrobial activity against Gram positive Bacillus subtilismicroorganisms in culture media. This reference does not anticipate thebenefits of combining hop extracts with Labiatae herb as described inthe present invention. The present invention does not require thepetitioning process taught by Kimura et al and avoids the use ofadditional processing expense.

[0024] D. Ninkov (International Application WO 01/15680 A1) teaches thatpharmaceutical compositions can be prepared by combining extracts ofessential oils from plants of the Labiatae family with an organic acidor group 1 salt. Ninkov teaches that the antimicrobial activity of thepharmaceutical composition is due to the presence of organic phenolssuch as isopropyl o-cresol in the oil extract from the plant.

[0025] K. Shetty and R. G. Labbe (Asia Pacific J. Clin. Nutr. (1998,7(3/4): 270-276.) describe work to clone Laminacae plants to produceenhanced levels of essential oil components such as carvacrol andthymol. These essential oil components have some antimicrobialproperties but their commercial use is prevented by the strong flavorsimparted to foods by these volatile compounds.

[0026] J. Campo, M. Amiot and C. Nguyen-the (2000, Journal of FoodProtection 63, pp. 1359-1368) teach that rosemary extract hasantimicrobial properties in culture studies. Minimum inhibitoryconcentrations varied with the species of bacteria being tested, butranged from 0.06-1%. Using up to one percent of an ethanolic solution ofrosemary had no effect on Gram negative bacteria. These researcherssuggest that rosemary extract may show promise in foods with low fat andlow protein content, but only against Gram positive organisms. No foodsystems were actually studied.

[0027] A. E. Down, et al., “Comparison of Vitamin E, NaturalAntioxidants and Antioxidant Combinations on the Lean Color and RetailCase-Life of Ground Beef Patties” published in October, 1999,http://www.ansi.okstate.edu/research/1999rr/04.htm describes the effectof rosemary extract in combination with other natural antioxidants andvitamin E diet supplementation on the color life of non-MAP ground beef.The slight increase in color life observed using natural antioxidantblend containing rosemary is statistically indistinguishable from thecontrol. This paper does not teach how to extend the microbial shelflife of meat.

[0028] A. E. Down, et al., “Influence of Vitamin E, Duralox®, andHerbalox® on Lean Color and Retail Case-Life of Ground Beef” publishedin October, 1999, http://www.ansi.okstate.edu/research/1999rr/05.htm,describes the effect of rosemary extract, rosemary extract incombination with other natural antioxidants and vitamin E on the colorlife of non-MAP ground beef. Addition of rosemary and rosemary plusother antioxidants increases the color life of the meat over thecontrol, but is not as effective as addition of Vitamin E. This paperdoes not teach how to extend the microbial shelf life of meat.

[0029] Our studies in actual meat systems show that rosemary extract,Herbalox® Seasoning, in which the majority of the volatile oilcomponents has been removed shows very little, if any, antimicrobialeffect. Herbalox® is a registered trademark of Kalsec®, Inc.

[0030] None of the prior art on the antimicrobial use of rosemary orother Labiatae herbs either anticipates or renders obvious the presentinvention. The prior art focuses on the use of herb essential oils. TheLabiatae herb extracts used in the present invention are processed in amanner that makes them essentially free of the native essential oil. Theprior art neither anticipates nor renders obvious the synergisticcombination of Labiatae herb extracts and hop extract. The prior artneither anticipates nor renders obvious the flavor masking effect ofLabiatae herb extracts on the bitter flavor of the hop extracts. Theprior art neither anticipates nor renders obvious the surprisinglybeneficial antimicrobial effect of the combination of Labiatae herbextract, hop extract and high oxygen atmosphere packaging on both Grampositive and Gram negative organisms.

OBJECTS OF THE INVENTION

[0031] An object of the present invention is to provide ways for meatmanufacturers to provide retailers with products from cost efficient,cost effective central processing centers.

[0032] A further object of the present invention is to providecompositions and methods of using them to extend the shelf life of freshmeat, fish and poultry.

[0033] A still further object of the invention is to provide fresh meat,fish and poultry that has extended microbial and color shelf life in anatmosphere containing 20% or more oxygen.

[0034] Yet another object of the invention is to provide a method forblocking the bitter flavor of hop extracts in fresh meats, fish andpoultry and allowing for the use of higher, and therefore effectiveinhibitory concentrations of hop extracts to be used without negativeflavor impacts.

SUMMARY OF THE INVENTION

[0035] We have discovered that hop extracts, preferably those containingbeta acids, in combination with Labiatae herb extracts, most preferablyrosemary extract, containing one or more of their natural constituents,carnosic acid, carnosol and/or rosmarinic acid, enhance the color shelflife and retard the growth of microorganisms in meat, fish and poultrystored in an atmosphere that contains 20% or more oxygen. Preferredherbs are rosemary, sage, oregano, thyme and mint.

[0036] Our invention provides singly or in combination:

[0037] A composition comprising a Labiatae herb extract and a hopextract containing beta acids.

[0038] A composition comprising a Labiatae herb extract containing aLabiatae herb acid selected from the group consisting of carnosic acid,carnosol, rosmarinic acid and mixtures thereof and a hop extractcontaining beta acids, such that the weight ratio of the beta acids tothe Labiatae herb acid is between about 0.5 and about 13.

[0039] A food selected from the group consisting of fresh meat, fish andpoultry containing a Labiatae herb extract and a hop extract containingbeta acids.

[0040] A food selected from the group consisting of fresh meat, poultryand fish containing a combination of a Labiatae herb extract and a hopextract containing beta acids, wherein the extracts are present in thefood in ratios which effectively extends the color and bacterial shelflife of the meat, fish or poultry in an atmosphere of 20% or moreoxygen.

[0041] A food selected from the group consisting of fresh meat, fish orpoultry containing 50-2000 ppm of a Labiatae herb extract and 40-1000ppm of a hop extract.

[0042] A food selected from the group consisting of fresh meat, fish orpoultry containing 10 ppm or more of Labiatae herb acid selected fromthe group consisting of carnosic acid, carnosol, rosmarinic acid andmixtures thereof and 20 ppm or more of beta acids.

[0043] A food selected from the group consisting of fresh meat, fish andpoultry containing between 19 and 500 ppm of Labiatae herb acid andbetween 30 and 300 ppm of beta acids.

[0044] A packaged food product comprising a food selected from the groupconsisting of fresh meat, fish and poultry containing a combination of aLabiatae herb extract and a hop extract containing beta acids, whereinthe extracts are present in the food in ratios which effectively extendsthe color and microbial shelf life of the fresh meat, fish or poultry inan atmoshere containing 20% or more of oxygen.

[0045] A method of extending the color shelf life of fresh meat, fish orpoultry which comprises, applying to or incorporating into said freshmeat, fish or poultry a color shelf life extending amount of a Labiataeherb extract and a hop extract containing beta acids and packaging thefresh meat, fish or poultry in an atmosphere containing 20% or moreoxygen.

[0046] A method of extending the microbial shelf life of fresh meat,fish or poultry stored in an atmosphere containing 20% or more oxygen,which comprises applying to or incorporating into said meat, fish orpoultry a microbial shelf life extending amount of a Labiatae herbextract and a hop extract containing beta acids and packaging the freshmeat, fish or poultry in an atmosphere containing 20% or more oxygen.The Labiatae herb extract and hop extract may be incorporated into thefresh meat, fish or poultry separately or together. The preferred methodis to incorporate them together in the form of a composition.

[0047] A method of inhibiting the growth of bacteria in food selectedfrom the group consisting of fresh meat, fish and poultry whichcomprises applying to or incorporating into the fresh meat, fish orpoultry a combination of a Labiatae herb extract and a hop extractcontaining beta acids and packaging the fresh meat, fish or poultry inan atmosphere containing 20% or more oxygen.

[0048] A method of inhibiting the growth of Gram negative bacteria infood selected from the group consisting of fresh meat, fish and poultrywhich comprises applying to or incorporating into the fresh meat, fishor poultry a combination of a Labiatae herb extract and a hop extractcontaining beta acids and packaging the fresh meat, fish and poultry inan atmosphere containing 20% or more oxygen. Preferred is a methodwherein the weight ratio of beta acids to Labiatae herb acid is betweenabout 0.5 and about 13.

[0049] A method for blocking the bitter taste of hop extract containingbeta acids that has been applied to or incorporated into fresh meat,fish or poultry which comprises also applying or incorporating Labiataeherb extract to the fresh meat, fish or poultry and packaging the freshmeat, fish or poultry in an atmosphere containing 20% or more oxygen.

[0050] A composition comprising a Labiatae herb extract containing aLabiatae herb acid selected from the group consisting of carnosic acid,carnosol, rosmarinic acid and mixtures thereof and a hop extractcontaining beta acids, such that the weight ratio of the beta acids tothe Labiatae herb acid is between about 0.5 and about 13.

[0051] The mixture of beta acids and Labiatae herb acids may be dilutedin one or more carriers, solubilizers or diluents consisting ofdecaglycerol monooleate (such as found in the commercial product Mazol®PGO 104k), fatty acid esters (such as found in Drewpol® 10-1-CC), benzylalcohol, ethyl alcohol, propylene glycol, vegetable oil, polysorbates,sorbitans, such as sorbitan trioleate, capric/caprylic triglycerides,and dextrose. Mazol® PGO 104k is a registered trademark of BASF.Drewpol® 10-1-CC is a registered trademark of Stepan, Inc.

[0052] The combination of Labiatae herb extract and hop extract isapplied to or incorporated into fresh meat, fish, or poultry byspraying, injecting, dipping, painting, vacuum tumbling, marinating,mixing, pumping, by dispersion on a carrier and combinations thereof.They can also be added together with additives such as polyphosphates,salt, water, flavors, broths, added proteins, sugars and starches incombined form or sequentially.

[0053] The Labiatae herb extract and the hop extract can be appliedseparately either in combination with other flavorings and adjuvants andemulsifiers or together as a single composition.

[0054] The preferred Labiatae herb extracts are obtained from rosemary,oregano, thyme, sage, and mint. Rosemary is most preferable. Theseextracts contain one or more of the Labiatae herb acids consisting ofcarnosic acid, carnosol, and rosmarinic acid.

[0055] Surprisingly, when incorporated into meat stored in anoxicconditions, under nitrogen, for example, the hop extracts alone, or hopextracts plus Labiatae herb extracts are completely ineffective asantimicrobial agents, showing that the presence of oxygen is critical tothe invention.

[0056] The invention is particularly suited for use with modifiedatmosphere packaged (MAP) meats. MAP meats are packaged in gasimpermeable materials that maintain an atmosphere above the product.Mixtures of oxygen and carbon dioxide are often used in MAP meats.Mixtures of these gases work very well with the present invention. Onemight think that the CO₂ present in a modified O₂/CO₂ atmosphere mightserve to lower the pH of the meat samples through formation of carbonicacid and increase the effectiveness of the hop acid, but pH measurementson the meats during storage show no differences between those storedunder N₂ and those stored under 80/20 O₂/CO₂. The pH remains in the 5.7to 6.2 range in both cases.

[0057] Prior art teaches that although minimum inhibitory concentrations(MIC) of beta acids are in the 1 ppm range in culture media, these MICsdo not translate well to complex food systems. Johnson, et al., citedabove, reports MIC for milk to be 1000 ppm (4% fat) and to be >10,000ppm for camembert cheese (˜24% fat). As fat content increases in foods,the antibacterial activity of hop acids decreases. These are similar toLarson's, et al., teaching (cited above), where 100 ppm was effective inskimmed milk, and 1000 ppm was required in whole milk. Prior artsuggests that hop acids may prove to be useful as antimicrobial agentsonly in low fat foods. We have found, surprisingly, that hop acids, andbeta acids in particular can be used in hamburger with fat contents of10-30%, or more. The most effective concentrations range from 20 to 200ppm beta acids. When hop acids alone are used at concentrations above 20ppm to 60 ppm in ground beef, depending upon the fat content,objectionable flavors are readily discernable. Surprisingly, theaddition of rosemary extracts, or extracts of other Labiatae herbs atsubliminal flavor levels masks the objectionable flavor, allowing foreffective concentrations of hop acids to be employed without a negativeflavor impact. Also, surprisingly, hop extracts and Labiatae herbextracts have been found to preserve color in MAP ground beef in asynergistic manner. In samples of ground beef stored 10 days in thedark, hop extract plus rosemary extract provides double the colorpreserving additive effect of hops or rosemary alone. Hop extracts aloneare prooxidant during light storage following dark storage of groundbeef whereas the combination of hop extract and rosemary extractprovides the best color stability under these conditions. Anothersurprising finding relates to the effect of the combination of hopextract, rosemary extract and oxygen containing modified atmospherepackaging on Gram negative bacteria.

[0058] The prior art is replete with statements that Hop extracts havelittle to no inhibitory effect on Gram negative organisms. Surprisingly,we have found evidence that beta acids in the presence of high oxygenconcentrations inhibit Aeromonas hydrophila and Escherichia coli, bothGram negative organisms. The combination of hop beta acids and highoxygen atmosphere also inhibits Serratia liquefaciens, a Gram negativeorganism isolated as a major spoilage organism in ground beef. Even moresurprisingly, the combination of rosemary and hop extracts showsynergistic inhibition of these Gram negative organisms, with the mostpronounced effects of synergism being seen under high oxygenatmospheres.

[0059] The combination of Labiatae herb extract and hop extractcontaining beta acids prolongs the color of fresh meat, fish and poultryin the presence of oxygen in a synergistic manner. Critical to thisinvention is the combination of rosemary extract or other effectiveLabiatae herb extract and beta acids and the presence of oxygen. Thebeneficial effect of the combination of Labiatae herb extract and hopbeta acids does not occur in the absence of oxygen.

[0060] Hop extract alone decreases the color life of fresh red meat(during storage in a lighted display case) and results in anunacceptable flavor. The combination of rosemary extract and hopsextracts acts synergistically to extend the color life of ground beef indark storage conditions. The combination is not just additive, but issynergistic, because it doubles the additive effect of hops alone androsemary alone.

[0061] The addition of Labiatae herb extract to beta acid containing hopextract increases the amount of bitter beta acids which can be toleratedflavor-wise to a level which is effective in preserving color and ininhibiting the growth of microorganisms in fresh meat, fish and poultry.

[0062] The combination of Labiatae herb extract, preferably, rosemaryextract, and hop extract containing beta acids is more effective insuppressing both Gram positive and Gram negative bacterial growth thaneither Labiatae herb extract or hop extract containing beta acids alone.Prior art shows that beta acids alone do not suppress Gram negativebacteria, whereas the combination of Labiatae herb, hop extract andoxygen does suppress them.

[0063] The combination of Labiatae herb extract and hop extractcontaining beta acids in the presence of oxygen, but not in its absence,improves the flavor of ground beef in a package after a commerciallydesirable storage period. Neither Labiatae herb extract or hop extractalone, or oxygen alone, or a combination of two of these factors alonepreserves flavor as well as the combination of the three at the end of acommercially desirable storage period.

DETAILED DESCRIPTION OF THE INVENTION

[0064] The present invention provides compositions comprising Labiataeherb extract and hop extract and methods for using said compositions forextending the shelf life of fresh meat, fish and poultry.

[0065] Before proceeding further with a description of the preferredembodiments of the invention, a number of terms will be defined.

[0066] Definitions

[0067] As use herein:

[0068] “Fresh meat, fish, and poultry” means entire carcasses, cutportions thereof, and ground portions thereof and may include additivessuch as polyphosphates, salt, water, flavors, broths, added proteins,sugar, starches and the like which are incorporated into the meat, fishor poultry. It is important to distinguish fresh meat, fish or poultrywhich may contain these ingredients and are covered by the presentinvention from cured meat, fish and poultry, which may contain the sameingredients, but also contain one or more of the following:erythorbates, erythorbic acid, ascorbates, ascorbic acid, nitrites,nirates or cultures. The present invention is limited to fresh meat,fish and poultry and does not include cured meat, fish or poultry.

[0069] “Hop extract means an extract of hops containing beta acids andoptionally other hop constituents present in the hops.

[0070] “Labiatae herb extract” means extract from a plant of theLabiatae genus, preferably rosemary, sage, oregano, thyme, mints andmixtures thereof. The most preferred is rosemary.

[0071] “Labiatae herb acid” means carnosic acid, carnosol, rosmarinicacid and mixtures thereof.

[0072] Materials and Methods

[0073] Hop extracts were obtained by extracting hops with super or subcritical carbon dioxide, or with food grade solvents. The hop extractscan be partitioned according to well known methods into fractionscontaining largely alpha acids and fractions containing largely betaacids. Extracts can also contain various gums, resins and other hop acidderivatives and hop constituents. Hop extracts containing the followingranges can be employed in this invention, but are not consideredlimiting:

[0074] Beta acids (lupulones) 20% to 100%

[0075] alpha acids (humulones) 0% to 50%

[0076] resins, waxes, etc. remainder of the composition of the extract.

[0077] Emulsifiers, edible solubilizing agents, and other adjuvants canbe added to aid in preparation and use of the hop extract formulations.

[0078] Rosemary herb extracts can be prepared by extracting rosemarywith food grade solvents or with supercritical carbon dioxide. Extractsconsisting largely of lipophillic components contain carnosic acid andcarnosol and other phenolic constituents. The amount of carnosic acid inthe extract can range from 0.5 to 50% or more. Carnosol contents canrange from 0.1 to 10% or more. Extracts consisting largely ofhydrophillic substances contain rosmarinic acid. Rosmarinic acid contentcan range from 0.1 to 35% or more, however, these concentrations in theextract are not considered limiting. Extracts made using solvents ofintermediate polarity contain both the lipophilic and hydrophiliccomponents. Carriers, such as vegetable oil, emulsifiers, propyleneglycol, edible solvents, and other adjuvants can be used in theformulations. Herbalox® Seasoning is a registered trademark of Kalsec®,Inc.

[0079] Extracts from oregano, sage, thyme and mint can be preparedutilizing methods well known in the art, including those described abovefor preparing rosemary extracts.

[0080] The extracts used in the present invention can either be in theform of both lipophilic and hydrophilic preparations alone or mixturesthereof. It is also within the scope of the present invention to combinethe Labiatae extracts and hop extracts with flavorings in the form ofspice extracts such as black pepper, celery, white pepper, garlic andonion or synthetic flavorings such as reaction flavors and glutamates.

[0081] The rosemary extract and hop extract containing beta acid werecombined in appropriate amounts and heated and stirred between 80-110°C. to give the concentrations used in the examples. As beta acids tendto crystallize out of the solution upon standing, samples were heatedthe morning of meat sample preparation to insure the beta acids werecompletely dissolved. Actual analysis of the combined rosemary and betaacid sample was performed to determine the amount of Labiatae herbextract and beta acids actually added to the meat.

[0082] Compositions utilizing oregano, sage, thyme, mint extracts andmixtures thereof can be prepared by combining the appropriate Labiataeherb extract or extracts with the hop extract as is described above forcompositions containing rosemary extract.

[0083] Preparation of Meat Samples

[0084] Coarse ground, vacuum packed ground chuck (˜19% fat) in 14 poundchubs was obtained from Hoekstra Meat Company. The ground chuck wasweighed into 17 pound batches and blended with the composition ofLabiatae herb extract and hop extract for 2 minutes in a Mainca RM-35meat mixer/blender. Blending was conducted by reversing the direction ofthe ribbon/paddle blades every 15 seconds during the two minute blendtime. Where a treatment was added, one half of the required amount ofcomposition was layered onto about half of the batch of meat initially,followed by the remaining half of the meat and then the remainingtreatment. Dry ice, crushed to a particle size of less than 1.7 mm, wasadded after 30 seconds of the two minute blending time to maintain themeat temperature between 28° F. to 32° F. during blending. Meat was thenground through a ⅛″ plate into one pound (±0.10#) samples. Ground meatwas packaged into Cryovac CD92 trays using a MAP packaging machine withbarrier film. An ILPRA Basic 100 VG single mold MAP packaging machineusing a heat seal temperature of 110° C. and heat seal time of 4 secondswas used to package the meat samples. Samples were sealed underatmospheres of 20% or more of oxygen, preferably 80% O₂ and 20% CO₂, or100% Nitrogen using a −700 mm Hg vacuum and +30 mm Hg gas back flush.Packaged meat was stored in the dark (32-35° F.) for a stated amount oftime, then, optionally, placed in the light box with 200 foot candlesCWF light, and a temperature of 32-35° F.

[0085] Samples were evaluated by colorimetry and headspace analysis.Color measurements were made using a Minolta CR-300 Chroma meter usingthe “C” light source and multi measure reading (average of threesuccessive readings) to measure the C.I.E. 1976 L* a* b* values.Colorimeter readings were taken through the film on the meat after thefilm had been cut from the package and pressed firmly against the meatto create a flat surface free from valleys and pockets of air. Threereadings along the diagonal of each package were taken. When calorimeterreadings were taken on MAP samples under nitrogen headspace, the MAPpackages were opened and allowed to rebloom for 10 minutes prior to themeasurements. CIE Lab color measurement system defines a threedimensional color space in which values L*, a* and b* are plotted atright angles to each other. L* is a measure along an axis representinglightness or darkness. A measure along a red/green axis gives a* and ameasure against a yellow/blue axis is represented by b*. CIE Lab is apopular color space for use in measuring reflective and transmissiveobjects. The a* value is widely used in the meat industry as a measureof redness. The higher the a*, the more acceptable, and the invention,by increasing the retention of a* over the control, allows an a* of even17 or higher to be achieved under commercial conditions.

[0086] The headspace gas composition was determined using a PBIDansensor Checkmate 9900 O₂/CO₂ analyzer to measure O₂ and CO₂concentrations on the packaged samples. Measurements were made using themanual spot test mode with a three second delay to flush the line and afive second measuring period. As the headspace and colorimetry analysesare destructive tests, samples were discarded after analysis.

[0087] Samples were analyzed on specific days as described in theexamples. The microbiological assays were performed by two independentand professionally qualified laboratories using AOAC Official Methods(988.18 and 991.14), and other appropriate analytical methods.

EXAMPLE 1

[0088] Demonstrating Beneficial Effect of a Combination of Hop Extractand Rosemary Extract on the Color and Microbial Shelf Life of HighOxygen Modified Atmosphere Packaged Ground Beef.

[0089] Ground Beef samples were prepared according to the methoddescribed in the Materials and Methods section and packaged in oxygenimpermeable packaging under an atmosphere of 80% oxygen and 20% carbondioxide. The treatments consisted of the following:

[0090] A. Control (no additives)

[0091] B. Rosemary extract (0.1% lipophilic rosemary extract added tomeat, giving final carnosic acid concentration in meat of approximately20 ppm.

[0092] C. Hop extract (0.1% hop extract added to meat, giving final betaacid concentration in meat of approximately 194 ppm.

[0093] D. Hop extract plus lipophilic rosemary extract (0.1% of acombination of lipophilic rosemary extract and hop extract added tomeat, giving final carnosic acid and beta acid concentrations in meat ofapproximately 20 ppm and 194 ppm, respectively.

[0094] The meat was stored in the dark and samples were pulled at days0, 5, 10, 18, and 21. These samples were analyzed to determine theeffect of the treatments on properties during dark storage. A number ofadditional samples were pulled at day 10 and placed in a lighted,refrigerated display case to simulate retail storage. Individual sampleswere pulled after 1, 2, 3, and 4 days additional storage in the light.

[0095] Table 1 shows the effect of the treatments on the total platecount (aerobic+anaerobic plate counts) in ground beef stored in the darkat 32-35 deg. Fahrenheit during storage. The Table clearly shows thatbeta acids drastically delay the growth of microorganisms in groundbeef. It further shows the dramatic synergistic effect of hops plusrosemary extracts. TABLE 1 Effect of Treatments on sum of Aerobic andAnaerobic Plate Count. 80% Oxygen/20% Carbon Dioxide Day A. Control B.Rosemary C. Hops D. Hops + Rosemary 0 6,500 3,270 2,500 8,100 5 73,00057,000 2,000 3,000 10 1,580,000 1,150,000 6,000 6,000 18 98,000,000116,000,000 7,000 4,000 21 320,000,000 270,000,000 1,510,000 344,000

[0096] Samples stored in the dark were analyzed for color. Color valueswere plotted out and fitted with least square lines. Using an a* valueof 17 as a value denoting a marginally acceptable color, the length oftime each sample took to reach a marginally acceptable a* value of 17was determined. These results are shown in Table 2, below. TABLE 2Effect of treatments on color stability of ground beef during darkstorage. Sample Initial a* Days to a* = 17 A. Control 27.5 13 B.Rosemary 25.9 15 C. Hops 27.4 14 D. Hops + Rosemary 27.4 19

[0097] Rosemary extract alone adds 2 days to the dark storage color lifeof the control. Hop extract adds only a single day. Together, if theeffect were additive, the combination should provide an additional 3days to the color life, namely 16 days. The combination actuallyprovides 6 days additional color life, showing a synergistic effect ofthe combination.

[0098] Table 3 shows the effect of the treatments on the color life ofground beef during storage under light after the ground beef had beenstored in the dark for 10 days previously. Again, a*=17 is used as a cutoff for acceptability, time to a*=17 is shown in the table. TABLE 3Effect of treatments on color stability of ground beef during lightstorage after 10 day's dark storage. Days in light to a* = 17 Sampleafter 10 days dark storage A. Control 2.1 C. Hops 1.4 D. Hops + Rosemary2.6

[0099] This data shows that beta alone is detrimental to the color lifeof the control during storage under fluorescent lighting.

EXAMPLE 2

[0100] Demonstrating the Ineffectiveness of a Combination of Hop Extractand Rosemary Extract on the Microbial Shelf Life of Modified AtmospherePackaged Ground Beef in the Absence of Oxygen.

[0101] The meat samples were prepared as in Example 1, except the meatwas packaged under nitrogen. Table 4 shows that none of the additivesare effective antimicrobial treatments for ground beef stored undernitrogen, showing that the presence of oxygen is critical to thisinvention. TABLE 4 Effect of Treatments on sum of Aerobic and AnaerobicPlate Count. 100% Nitrogen Day A. Control B. Rosemary C. Hops D. Hops +Rosemary 0 6,500 3,270 2,500 8,100 5 102,000 144,000 98,000 21,000 108,100,000 6,700,000 1,260,000 630,000 18 74,000,000 65,000,00031,000,000 36,000,000

EXAMPLE 3

[0102] Demonstrating Dose Response of Beta Acids as an AntimicrobialTreatment in MAP Packaged Ground Beef. Demonstrating that doses between50 and 100 ppm are optimal to protect 19% fat containing ground beef.

[0103] Ground beef samples were prepared according to the methoddescribed in the Materials and Methods section and packaged in oxygenimpermeable packaging under an atmosphere of 80% oxygen and 20% carbondioxide. The treatments consisted of the following:

[0104] A. Control (no additives)

[0105] B. Lipophilic Rosemary extract (0.1% lipophilic rosemary extractadded to meat, giving final carnosic acid concentration in meat ofapproximately 20 ppm.

[0106] C. Hop extract plus lipophilic rosemary extract (0.1% of acombination of lipophilic rosemary extract and hop extract added tomeat, giving final carnosic acid and beta acid concentrations in meat ofapproximately 20 ppm and 194 ppm, respectively.

[0107] D. Hop extract plus lipophilic rosemary extract (0.1% of acombination of lipophilic rosemary extract and hop extract added tomeat, giving final carnosic acid and beta acid concentrations in meat ofapproximately 20 ppm and 105 ppm, respectively.

[0108] E. Hop extract plus lipophilic rosemary extract (0.1% of acombination of lipophilic rosemary extract and hop extract added tomeat, giving final carnosic acid and beta acid concentrations in meat ofapproximately 20 ppm and 50 ppm, respectively.

[0109] F. Hop extract plus lipophilic rosemary extract (0.1% of acombination of lipophilic rosemary extract and hop extract added tomeat, giving final carnosic acid and beta acid concentrations in meat ofapproximately 20 ppm and 10 ppm, respectively.

[0110] The meat was stored in the dark and samples were pulled at days0, 5, 10, and 18 and analyzed for aerobic and anaerobic plate count.

[0111] Table 5 shows that the effect is dependent on dose and that adose of greater than about 50 ppm beta is required to get the desiredcommercially acceptable effect in this specific meat. This will bedependent upon the initial bacterial load of the starting meat. Theinvention is most effective in meats prepared under sanitary conditions.TABLE 5 Effect of Treatments on sum of Aerobic and Anaerobic PlateCount. Effect of Beta Acid Dose C. D. D. D. Rose. + 194 ppm Rose. + 105ppm Rose. + 50 ppm Rose. + 10 ppm Day A. Cont. B. Rose. beta beta betabeta 0 300 300 600 200 200 900 5 25,000 9,600 1,000 2,100 3,200 6,900 102,500,000 900,000 1,100 32,000 370,000 1,480,000 18 127,000,000124,000,000 1,800 160,000 68,000,000 129,000,000

EXAMPLE 4

[0112] Demonstrating the effectiveness of hydrophilic extracts ofrosemary in combination with hop beta acids and high oxygen atmospherepackaging.

[0113] Ground beef samples were prepared according to the methoddescribed in the Materials and Methods section and packaged in oxygenimpermeable packaging under an atmosphere of 80% oxygen and 20% carbondioxide. The treatments consisted of the following:

[0114] A. Control (no additives)

[0115] B. Hydrophilic rosemary extract (0.1% hydrophilic rosemaryextract added to meat, giving final rosmarinic acid concentration inmeat of approximately 32 ppm.

[0116] C. Hydrophilic rosemary extract plus hop extract (0.1% of acombination of hydrophilic rosemary extract and hop extract added tomeat, giving final rosmarinic acid and beta acid concentrations ofapproximately 32 and 194 ppm, respectively.

[0117] The effect of these treatments on aerobic plus anaerobic platecounts is shown in Table 6. TABLE 6 Effect of Treatments on sum ofAerobic and Anaerobic Plate Count. Hydrophilic rosemary extracts. B.Hydrophilic C. Hydrophilic Day A. Control Rosemary Rosemary + Beta 0 300400 200 5 25,000 11,200 3,000 10 2,500,000 840,000 222,000 18127,000,000 165,000,000 20,000,000

EXAMPLE 5

[0118] Demonstrating the flavor protecting effect of rosemary extract onmeat samples containing hop beta acids.

[0119] Meat samples were prepared by blending the appropriate amounts ofhop and/or rosemary extracts with ground beef of 10, 20 and 30% fatcontents. Ground beef samples were cooked on a broiler to an internaltemperature of 155 degrees F. Panels were conducted while ground beefwas still warm. Thresholds were determined using an ascendingforced-choice method (n=20 panelists). Triangle tests were performedwith various concentrations of beta acids (with and without rosemaryextract) as the odd sample. The threshold values represent theconcentration where the number of panelists selecting the odd sample wasnot significant (low value of the range) and the lowest concentrationwhere the number of panelists selecting the odd sample was significant(high value of the range). Values are given in ppm of beta acids inTable 7. Rosemary extract concentration was 0.1 wt %. TABLE 7 FlavorThresholds for Beta in Ground Beef in the Absence and Presence ofRosemary Extract. Beta Acids in Beta Acids + Rosemary Meat Block(lean/fat) Hop Extract Extract 90/10 <20 ppm  40-60 ppm 80/20 <40 ppm 60-80 ppm 70/30 <60 ppm 80-100 ppm

[0120] A difference from control test with 45 panelists revealed asignificant decrease in off-flavor scores for Herbalox (0.1%)+beta (150ppm) compared with beta. This shows that rosemary extract masks thebitterness of the hop extract containing beta acid, which is unexpected,since rosemary extracts do not contain sweet or other substances whichmight overpower the bitterness.

[0121] We have found surprising and synergistic effects of hop extractscontaining beta acids combined with rosemary extracts on inhibition ofanaerobic and aerobic Gram negative and Gram positive bacterial growthin culture medium and in red meat.

[0122] As reported in the prior art literature, beta and other hop acidshave an inhibitory effect on gram positive bacteria, some of which arepathogenic. They are believed, however, to have no inhibitory effects ongram negative bacteria, some of which are pathogenic and which alsocontribute to spoiling and discoloration of meat. As the followingexamples will show, this is not the case in atmospheres of elevatedoxygen, and some species are even inhibited in atmospheres of normalair, which is about 20% oxygen. However, atmospheres above 40%, andpreferably above 60%, and most preferably in the 70% to 80% and aboveoxygen are preferred, with the other gas being CO2.

[0123] The procedures for evaluating three species of common bacteriawere performed as follows:

[0124] Three different genera of Gram negative bacteria were tested. Theprocedure employed Enriched Nutrient Agar plates seeded with freshbacterial cultures spread over the plate to give a lawn of bacterialgrowth after incubation at 22° C. Whatman 3 mm paper disks (8 mmdiameter) containing the test compounds at designated dose levels in 95%ethanol were placed on the plates after allowing the disks to dry in asterile environment. The hop extract used to dose the disks contained1.29 g beta acids in 10 ml of ethanol, and different amounts of theethanolic solution was used to provide different doses of beta acids tothe disks used in the tests. In the experiments to test the combinedeffects of rosemary and hop extracts, the rosemary extract was added tothe enriched nutrient agar directly at levels of 500, 1000 and 2000 ppm.The rosemary extract used for dosing the agar contained 7.4% carnosicacid and 1.0% carnosol and 2.7% rosmarinic acid. The rosemary extract(an ethanol extract) was dissolved in 95% ethanol at a rate of 2.63grams per 10 ml of ethanol. Appropriate amounts of this solution wereadded to the Agar to give the concentrations used in the experiment. Theagar containing 1000 ppm rosemary extract contained approximately 74 ppmcarnosic acid, 10 ppm carnosol and 27 ppm rosmarinic acid. A controldisk dipped in ethanol was also placed on the plate. Clear zones in thebacterial lawn (confluent bacterial growth) around the disks, measuredin mm, after incubation in various atmospheres were used to estimateextent of antibacterial activity of the compounds added to the disks.Zones of inhibition were measured in millimeters. The disks are 8 mm,thus 9 mm means that there was 1 mm zone of inhibition around the disc.A 0 means no zone of inhibition was observed. In all cases, noinhibition was observed around the control disks. These plate assaysreveal that the concentration of bacteria used to innoculate the platewas critical for the observation of the clear zones which indicateantibacterial activity. Assays were performed with three plates. Thesecond plate was innoculated with one tenth the number of bacteria asthe first plate and the third plate was innoculated with one tenth theamount of bacteria as the second. In all cases studied, the zones ofinhibition increased with decreasing initial bacterial load.

EXAMPLE 6

[0125] Demonstrating the inhibitory effects on Aeromonas hydrophilastrain ATCC7965.

[0126] The results, in Tables 8, 9 and 10, show that inhibition occurswith beta alone, is dose dependent, and that rosemary extract enhancesthe inhibition and is also dose dependent in the presence of oxygen. An80-20 oxygen atmosphere is much more effective than air, and at thehighest rosemary dose the inhibition was TLM (too large to measure).Surprisingly, rosemary shows a negative influence on the activity ofbeta acids in anoxic conditions. TABLE 8 Measure of inhibition onAeromonas hydrophila ATCC 7965 under air (21% oxygen). Zone ofinhibition (in mm) No 500 ppm 1000 ppm 2000 ppm Beta Acid RosemaryRosemary Rosemary Rosemary on disk in Agar in Agar in Agar in Agar 1.29μg 14 11 14 16 2.58 μg 18 15 18 20 3.87 μg 20 18 20 25

[0127] TABLE 9 Measure of inhibition on Aeromonas hydrophila ATCC 7965under 80% oxygen and 20% carbon dioxide. Zone of inhibition (in mm) No500 ppm 1000 ppm 2000 ppm Beta Acid Rosemary rosemary rosemary rosemaryon disk in Agar in Agar in Agar in Agar 1.29 μg 12 16 28 TLM 2.58 μg 1818 32 TLM 3.87 μg 28 32 36 TLM

[0128] TABLE 10 Measure of inhibition on Aeromonas hydrophila ATCC 7965under Nitrogen. Zone of inhibition (in mm) No 500 ppm 1000 ppm 2000 ppmBeta Acid Rosemary rosemary rosemary rosemary on disk in Agar in Agar inAgar in Agar 1.29 μg 15 12 9 9 2.58 μg 19 15 9 9 3.87 μg 22 20 9 9

EXAMPLE 7

[0129] Demonstrating the inhibitory effects on Escherichia coli ATCCstrain 25922. The results are given in Tables 11, 12, and 13. There wasno inhibition by beta alone or beta plus rosemary in an anoxicatmosphere. There was significant inhibition in air, and much superiorinhibition in an 80/20 oxygen/carbon dioxide atmosphere. The inhibitionwas dose dependent for both beta acids and beta acids plus rosemary. Thepresence of rosemary approximately doubled the effectiveness of the betaacids. TABLE 11 Measure of inhibition on Escherichia coli ATCC 25922under air (21% oxygen). Zone of inhibition (in mm) No 500 ppm 1000 ppm2000 ppm Beta Acid Rosemary Rosemary Rosemary Rosemary on disk in Agarin Agar in Agar in Agar 1.29 μg 0 0 9 12 2.58 μg 0 9 9 14 3.87 μg 10 910 16

[0130] TABLE 12 Measure of inhibition on Escherichia coli ATCC 25922under 80% oxygen and 20% carbon dioxide. Zone of inhibition (in mm) No500 ppm 1000 ppm 2000 ppm Beta Acid Rosemary Rosemary Rosemary Rosemaryon disk in Agar in Agar in Agar in Agar 1.29 μg 0 0 16 24 2.58 μg 10 1418 24 3.87 μg 12 18 20 24

[0131] TABLE 13 Measure of inhibition on Escherichia coli ATCC 25922under Nitrogen. Zone of inhibition (in mm) No 500 ppm 1000 ppm 2000 ppmBeta Acid Rosemary Rosemary Rosemary Rosemary on disk in Agar in Agar inAgar in Agar 1.29 μg 0 0 0 0 2.58 μg 0 0 0 0 3.87 μg 0 0 0 0

EXAMPLE 8

[0132] Demonstrating the inhibitory effects on Serratia liquefaciens.Serratia liquefaciens was isolated from a ground meat sample. Theresults of the zone inhibition tests are given in Tables 14, 15, and 16.Under anoxic conditions, only the highest dose of beta acids alone waseffective, but lower doses were effective in the presence of rosemary.The highest dose of rosemary, 2000 ppm, had no effect. Performance wasimproved in the presence of air, and the improvement was greater in an80/20 atmosphere. TABLE 14 Measure of inhibition on Serratialiquefaciens under air (21% oxygen). Zone of inhibition (in mm) No 500ppm 1000 ppm 2000 ppm Beta Acid Rosemary Rosemary Rosemary Rosemary ondisk in Agar in Agar in Agar in Agar 1.29 μg 0 0 0 0 2.58 μg 0 0 0 03.87 μg 0 9 0 0

[0133] TABLE 15 Measure of inhibition on Serratia liquefaciens under 80%oxygen and 20% carbon dioxide. Zone of inhibition (in mm) No 500 ppm1000 ppm 2000 ppm Beta Acid Rosemary Rosemary Rosemary Rosemary on diskin Agar in Agar in Agar in Agar 1.29 μg 0 0 0 0 2.58 μg 9 0 14 12 3.87μg 12 10 16 15

[0134] TABLE 16 Measure of inhibition on Serratia liquefaciens underNitrogen. Zone of inhibition (in mm) No 500 ppm 1000 ppm 2000 ppm BetaAcid Rosemary Rosemary Rosemary Rosemary on disk in Agar in Agar in Agarin Agar 1.29 μg 0 10 9 0 2.58 μg 0 11 9 0 3.87 μg 10 12 9 0

[0135] These examples show that different Gram negative organismsrespond differently at given dosage levels, but that all aresignificantly more responsive under increasing oxygen atmospheres. Theyalso show that rosemary dosage generally has a positive effect on theinhibition, but that overdosing of rosemary may have a negative effect.

[0136] Since inhibition is greater and more long lasting for lowerinoculation rates in the media, optimum dosing in commercial practicewill depend upon the initial bacterial load in the meat. The dosage andcombination can be determined by one of reasonable skill in the art.

EXAMPLE 9

[0137] Ground beef was prepared and dosed as in the procedure describedabove in the Materials and Methods section. It was incubated at 4° C.for 16 days in the dark under an 80/20 oxygen/carbon dioxide atmosphere.At this time, samples were withdrawn and the number of colony formingunits determined in a culture medium. The number of colony forming unitswas approximately half in the beta acid and beta acid+rosemary samples.These colonies consist of aerobic and anaerobic bacteria, and thereforethe example shows that both Gram positive and Gram negative types ofbacteria are inhibited by the treatment. This supports Example 1 and isanother example in fresh meat.

EXAMPLE 10

[0138] Ground beef containing about 30% fat obtained from a secondcommercial source was dosed with rosemary extract containing carnosicacid, with sufficient hop extract to provide 75 ppm beta acids and 19ppm carnosic acid in the rosemary extract, 150 ppm beta acids in the hopextract and 19 ppm carnosic acid in the rosemary extract, and soybeanoil as a control. The ground beef was packaged in an 80/20 atmosphere inoxygen impermeable plastic. The samples were evaluated for bacterialcount at the end of 12 days dark storage and 2 days light storage, bothat 4° C., under an 80/20 atmosphere. The beef was then macerated andcultured, and the number of colony forming units in two meat samplesfrom each treatment was evaluated after incubating at 22° C. for 48hours. The results of five replicates of each treatment were averaged.Neither the rosemary alone or the control were significantly different,but both the combinations of rosemary and hop extract had a third orless of the number of colony forming units than the control or rosemaryalone.

[0139] A second evaluation of the same meat samples by the standard AOACOfficial Method 990.12 for aerobic Plate Count in Foods, and by theprocedure from the “Compendium of Methods for the MicrobiologicalExamination of Foods”, Ch 9 of the 3^(rd) edition for anaerobic platecount, was performed. Five samples from each treatment were assayed forboth anaerobic and aerobic bacterial count, after 12 days in the darkand 2 days in the light at 4° C. The results are reported in Table 17.TABLE 17 Effect of Hop extract and Rosemary Extract on Anaerobic andAerobic Plate Count of 30% Fat Ground Beef. Plate Count, Plate Count, inBeta Acid Carnosic Acid in thousands thousands Dose, ppm Dose, ppmAnaerobic Aerobic 0 19 568 438 75 19 286 58 150 19 434 56 0 0 648 532

[0140] Both results show that both combinations of hop extract androsemary extract suppressed aerobic and anaerobic bacteria significantlymore than either the rosemary alone or the control.

[0141] They are consistent with the synergistic suppression of theanaerobic bacteria in culture media by a combination of rosemary and hopextract.

EXAMPLE 11

[0142] Demonstrating the Effect of a Range of Rosemary ExtractConcentration in Combination with Hop Extract on the Color and MicrobialShelf Life of High Oxygen Modified Atmosphere Packaged Ground Beef.

[0143] Ground beef samples were prepared according to the methoddescribed in the Materials and Methods section and packaged in oxygenimpermeable packaging under an atmosphere of 80% oxygen and 20% carbondioxide. The treatments provided meat with approximately 117 ppm hopbeta acids and a range of rosemary extract concentrations. The samplesprovided from 9 to 74 ppm carnosic acid in the final meat product.Analysis of total plate count showed that changing the rosemary extractconcentration over this range did not have a significant effect on theantibacterial activity.

EXAMPLE 12

[0144] Demonstrating the high oxygen atmosphere packaging of ground porktreated with a combination of hop beta acids and rosemary extract.

[0145] Fresh ground pork is treated with a composition of a hop extractproviding a level of 100 ppm hop beta acid and a lipophilic rosemaryextract providing approximately 20 ppm carnosic acid. The ground pork ispackaged under an atmosphere of 80% oxygen and 20% carbon dioxide, byvolume, in oxygen impermeable packaging material.

EXAMPLE 13

[0146] Demonstrating the antimicrobial effect of hop beta acids in fish.

[0147] Approximately 500 ppm in an acetone solution was added toapproximately 2 grams of manually homogenized smelt tissue. A controlsmelt tissue was spiked with an equivalent amount of acetone only(approx. 200 mcl). The 20 ml glass vials containing these tissuepreparations were capped and stored at ambient temperature forapproximately 24 hours. Interestingly, the stored beta/smelt homogenatelacked the unpleasant spoiled, fishy odor that was overwhelminglynoticeable in the control tissue.

EXAMPLE 14

[0148] Demonstrating a convenient liquid formulation of hop beta acidsand rosemary extract suitable for application to fresh meat, fish orpoultry.

[0149] A liquid composition is prepared by combining from 5-49% byweight decaglycerol tetraoleate (Mazol® PGO 104k) with 25-55% lipophilicand/or hydrophilic rosemary extract, 5-40% hop extract containing hopbeta acids, and 20-40% vegetable oil. The mixture can be heated tosolubilize the components. The percentages of each ingredient dependsupon the concentration of the active constituents in each extract, whichvary according to the raw material from which they are produced, and canbe adjusted by one skilled in the art to provide a composition whichdelivers effective amounts of the hop extract and rosemary components tothe meat. Other, less preferred, solubilizers or diluents can be used tomake this liquid composition. These include, benzyl alcohol, ethylalcohol, polysorbate emulsifiers, sorbitans, fatty acid esters, and monoand diglycerides.

EXAMPLE 15

[0150] Demonstrating the use of rosemary extract and hop extract incombination with other flavorings. Coarse ground beef is treated with0.1% of a mixture of rosemary extract and a hop extract such that themeat contains about 25 ppm carnosic acid and about 125 ppm hop betaacids. The meat is also treated with 0.02% celery extract in the form ofAquaresin® Celery and 0.04% black pepper extract in the form ofAquaresin® Black Pepper. The meat is re-ground through a ⅛″ screen andpackaged in oxygen impermeable packaging material under an 80% oxygen,20% carbon dioxide atmosphere. Aquaresin® is a registered trademark ofKalsec®, Inc.

EXAMPLE 16

[0151] Demonstrating the use of purified constituents of Labiatae herbextract and hop extract in ground beef. Coarse ground beef is treatedsequentially with an aqueous solution of hop beta acids at a pH of 12and a solution of carnosic acid in ethanol such that the finalconcentration of hop beta acids in the meat upon addition is 60 ppm andthe final concentration of carnosic acid in the meat upon addition is 15ppm. The meat is re-ground through a ⅛″ screen and packaged in oxygenimpermeable packaging material under an 80% oxygen, 20% carbon dioxideatmosphere.

EXAMPLE 17

[0152] Demonstrating the preparation of a composition containingpurified Labiatae herb acids and hop beta acids. One hundred grams of acomposition useful for extending the color and bacterial shelf life offresh meat, fish and poultry is prepared by combining 10 grams of hopbeta acids and 15 grams of decaglycerol tetraoleate and heating theresulting mixture to about 50-80° C. Four grams of carnosic acid and 71grams of vegetable oil is then added and the resulting mixture is heatedto between 80-110° C. for about five minutes with stirring. Ahomogeneous liquid is formed. This liquid can be added at various dosesto fresh meat, fish and poultry to provide shelf life extension.

[0153] Utilizing a procedure similar to that described above butsubstituting carnosol for carnosic acid, a homogeneous liquid containingcarnosol and hop beta acids is obtained.

[0154] One hundred grams of a composition containing purified rosmarinicacid and hop beta acids is prepared by combining 10 grams of hop betaacids, 4 grams of rosmarinic acid and 86 grams of propylene glycol. Theresulting mixture is heated to between 80-110° C. for about five minuteswith stirring to yield a homogeneous liquid containing rosmarinic acidand hop beta acids.

[0155] It is shown that the combination of a hop extract containing aneffective amount of beta acids and a rosemary or other Labiatae extractcontaining effective amounts of carnosic acid, carnosol, and/orrosmarinic acid have a synergistic effect on preserving the color andreducing both Gram positive and Gram negative bacterial growth in meat,fish and poultry packaged in an oxygen containing atmosphere, andpreferably in an elevated oxygen atmosphere with the remainder of thegas being CO₂ or a mixture of CO₂ and N₂. These novel effects enablemeat processors to provide MAP packaged meats of acceptable appearanceand bacterial counts under commercially feasible distribution anddisplay conditions, and thereby afford a new means of offering consumersmeat, fish and poultry of superior quality and lower bacterial counts.Since the inhibitory combination of natural flavorings is not fed toanimals from which red meats are derived, it does not run the risk ofcreating antibiotic resistant bacterial strains, which is an adverseeffect of the use of antibiotics in animal feeds.

[0156] The results show that color retention is improved and bacterialgrowth diminished by the synergistic combination of an effective amountof hop extract containing beta acids and an effective amount of rosemaryextract or other Labiatae herb extract containing carnosic acid,optionally carnosol, and optionally rosmarinic acid, or essentiallyrosmarinic acid, provided oxygen is present at 20% or more, andpreferably 40% or more, and more preferably at 60% or more, and mostpreferably at 70-80% or above, and with CO₂ preferably consisting of theother gas, and less preferably a mixture of CO₂ and nitrogen. Theinvention also pertains to the masking of the hop extract flavor by therosemary extract, which results in being able to use higher, and thusmore effective amounts of hop extracts without causing negative flavorimpacts.

[0157] It is to be understood that the invention is not to be limited tothe exact details of operations, or to the exact compositions, methods,procedures, or embodiments shown and described, as obvious modificationsand equivalents will be apparent to one skilled in the art, and theinvention is therefore to be limited only by the full scope which can belegally accorded to the claims hereof.

What is claimed is:
 1. A composition comprising a hop extract containingbeta acids and a Labiatae herb extract.
 2. A composition according toclaim 1, wherein the Labiatae herb extract contains a Labiatae herb acidselected from the group consisting of carnosic acid, carnosol,rosmarinic acid and mixtures thereof, and wherein the weight ratio ofthe beta acids to the Labiatae herb acid is between about 0.5 and about13.
 3. A composition according to claim 2, wherein the Labiatae herbextract is selected from the group consisting of rosemary extract,oregano extract, thyme extract, sage extract, mint extract and mixturesthereof.
 4. A composition according to claim 3, wherein the Labiataeherb extract is rosemary extract.
 5. A composition according to claim 3,wherein the Labiatae herb extract is oregano extract.
 6. A compositionaccording to claim 3, wherein the Labiatae herb extract is thymeextract.
 7. A composition according to claim 3, wherein the Labiataeherb extract is sage extract.
 8. A composition according to claim 3,wherein the Labiatae herb extract is mint extract.
 9. A compositionaccording to claim 3, wherein the Labiatae herb extract is selected fromthe group consisting of mixtures of rosemary, oregano, thyme, sage andmint extracts.
 10. A composition according to claim 2, wherein theLabiatae herb acid is selected from the group consisting of mixtures ofcarnosic acid, carnosol and rosmarinic acid.
 11. A composition accordingto claim 1, wherein the hop extract consists essentially of a mixture ofbeta acids.
 12. A composition comprising a Labiatae herb extract and ahop extract containing beta acids, wherein the Labiatae herb extract andhop extract are present in amounts that are effective in prolonging thecolor and microbiological stability of meat, poultry, or fish in anatmosphere containing 20% or more of oxygen and optionally another gasselected from the group consisting of carbon dioxide and a mixture ofcarbon dioxide and nitrogen.
 13. A composition according to claim 12,wherein the composition is effective in prolonging the color andmicrobiological stability of fresh meat, poultry, or fish in anatmosphere containing 40% or more oxygen and optionally another gasselected from the group consisting of carbon dioxide and a mixture ofcarbon dioxide and nitrogen.
 14. A composition according to claim 13,wherein the composition is effective in prolonging the color andmicrobiological stability of fresh meat, poultry, or fish in anatmosphere containing 60% or more oxygen and optionally another gasselected from the group consisting of carbon dioxide and a mixture ofcarbon dioxide and nitrogen.
 15. A composition according to claim 14,wherein the composition is effective in prolonging the color andmicrobiological stability of fresh meat, poultry, or fish in anatmosphere containing 70% or more oxygen and optionally another gasselected from the group consisting of carbon dioxide and a mixture ofcarbon dioxide and nitrogen.
 16. A composition according to claim 12,wherein the Labiatae herb is rosemary.
 17. A composition according toclaim 12, wherein the Labiatae herb is oregano.
 18. A compositionaccording to claim 12, wherein the Labiatae herb is thyme.
 19. Acomposition according to claim 12, wherein the Labiatae herb is mint.20. A composition according to claim 12, wherein the Labiatae herb issage.
 21. A composition comprising a Labiatae herb extract, a hopextract containing beta acids and a carrier selected from the groupconsisting of decaglycerol monooleate, fatty acid esters, benzylalcohol, ethyl alcohol, propylene glycol, vegetable oil, polysorbates,sorbitans, sorbitan trioleate, capric/caprylic triglycerides, dextroseand combinations thereof.
 22. A composition according to claim 21, thatadditionally contains flavorings and adjuvants.
 23. A compositionaccording to claim 21, wherein the herb extract is a Labiatae herb acidselected from the group consisting of carnosic acid, rosmarinic acid andcombinations thereof, and wherein the weight ratio of beta acids toLabiatae acid is between about 0.5 and about
 13. 24. A liquidcomposition according to claim 21, which contains from 5-49% by weightof a solubilizer or diluent selected from the group consisting ofdecaglycerol tetraoleate, benzyl alcohol, ethyl alcohol, propyleneglycol, polysorbate emulsifiers, sorbitans, fatty acid esters, mono- anddiglycerides, and mixtures thereof, 25-55% of a rosemary herb extractselected from the group consisting of lipophilic rosemary extract,hydropholic rosemary extract and mixtures thereof, 5-40% hop extractcontaining hop beta acids and 20-40% vegetable oil.
 25. A food selectedfrom the group consisting of fresh meat, poultry, and fish containing acombination of a Labiatae herb extract and a hop extract containing betaacids, wherein the extracts are present in the food in ratios whicheffectively extends the color and bacterial shelf life of the meat,poultry, or fish in an atmosphere of 20% oxygen or more.
 26. A foodaccording to claim 25, wherein the Labiatae herb extract is derived fromrosemary.
 27. A food according to claim 25, wherein the Labiatae herbextract is derived from oregano.
 28. A food according to claim 25,wherein the Labiatae herb extract is derived from thyme.
 29. A foodaccording to claim 25, wherein the Labiatae herb extract is derived frommint.
 30. A food according to claim 25, wherein the Labiatae herbextract is derived from sage.
 31. A food according to claim 25, whereinthe hop extract consists essentially of beta acids.
 32. A food accordingto claim 25, containing 10 ppm or more of Labiatae herb acid selectedfrom the group consisting of carnosic acid, carnosol, rosmarinic acidand mixtures thereof and 20 ppm or more of beta acid.
 33. A foodaccording to claim 32, containing between 19 and 500 ppm of Labiataeherb acid and between 30 and 300 ppm of beta acids.
 34. A packaged foodproduct comprising a food according to claim 25, wherein the food hasbeen packaged by modified atmosphere packaging in an atmospherecomprising 20% or more oxygen and optionally a gas selected from thegroup consisting of carbon dioxide and a mixture of carbon dioxide andnitrogen.
 35. A packaged food product according to claim 34, theatmosphere contains more than 40% oxygen.
 36. A packaged food productaccording to claim 35, wherein the atmosphere contains more than 60%oxygen.
 37. A packaged food product according to claim 36, wherein theatmosphere contains more than 70% oxygen.
 38. A method for preparingpackaged fresh meat, fish or poultry containing a Labiatae herb extractand a hop extract, which comprises applying to or incorporating intofresh meat, fish or poultry a composition comprising Labiatae herbextract and hop extract and then packaging the fresh meat, fish orpoultry in an atmosphere that contains 20% or more oxygen.
 39. A methodaccording to claim 38, wherein the Labiatae herb extract is rosemaryextract.
 40. A method for extending the color life and inhibitingbacterial growth in fresh meat, fish, or poultry in an atmosphere of 20%oxygen or more which comprises applying to or incorporating into saidfresh meat, fish or poultry a Labiatae herb extract and a hop extractcontaining beta acids and then packaging the fresh meat, fish or poultryin an atmosphere that contains 20% or more oxygen.
 41. A methodaccording to claim 40, wherein the Labiatae herb extract and hop extractare applied to or incorporated into the fresh meat, fish or poultry inthe form of a composition.
 42. A method according to claim 40, whereinthe Labiatae herb extract is applied to or incorporated into the freshmeat, fish or poultry separately.
 43. A method according to claim 40,wherein the composition is applied to or incorporated into the freshmeat, fish or poultry by spraying, injecting, dipping, painting, vacuumtumbling, marinating, mixing, pumping, dispersion on a carrier andcombinations thereof.
 44. A method for blocking the bitter taste of hopextract that has been applied to fresh meat, poultry or fish whichcomprises applying the hop extract in combination with Labiatae herbextract to said meat, fish or poultry.
 45. A method according to claim44, wherein the Labiatae herb extract contains a Labiatae acid selectedfrom the group consisting of carnosic acid, carnosol, rosmarinic acidand mixtures thereof.
 46. A method according to claim 45, wherein theweight ratio of beta acids to Labiatae acid is between 0.5 and
 13. 47. Amethod of extending the microbial shelf life of fresh meat, fish orpoultry stored in an atmosphere comprising 20% or more oxygen, whichcomprises applying to or incorporating into the fresh meat, fish orpoultry a microbial shelf life extending amount of a Labiatae herbextract and a hop extract containing beta acids and then packaging thefresh meat, fish or poultry in an atmosphere that contains 20% or moreoxygen.
 48. A method according to claim 47, wherein the Labiatae herbextract contains a Labiatae herb acid selected from the group consistingof carnosic acid, carnosol, rosmarinic acid and mixtures thereof.
 49. Amethod according to claim 48, wherein the weight ratio of beta acids toLabiatae herb acid is between about 0.5 and about
 13. 50. A method ofinhibiting the growth of bacteria in food selected from the groupconsisting of fresh meat, fish and poultry which comprises applying toor incorporating into the fresh meat, fish or poultry a combination of aLabiatae herb extract and a hop extract containing beta acids and thensubjecting the fresh meat, fish or poultry to modified atmosphericpackaging.
 51. A method according to claim 50, wherein the Labiatae herbextract contains a Labiatae herb acid selected from the group consistingof carnosic acid, carnosol, rosmarinic acid and mixtures thereof.
 52. Amethod according to claim 51, wherein the weight ratio of beta acids toLabiatae herb acid is between about 0.5 and about
 13. 53. A methodaccording to claim 50, wherein the bacteria is a Gram negative bacteria.54. A method according to claim 53, wherein the Labiatae herb extractcontains a Labiatae herb acid selected from the group consisting ofcarnosic acid, carnosol, rosmarinic acid and mixtures thereof.
 55. Amethod according to claim 54, wherein the ratio of beta acids toLabiatae herb acid is between about 0.5 and about
 13. 56. A methodaccording to claim 53, wherein the Gram negative bacteria is Aeromonashydrophilla.
 57. A method according to claim 53, wherein the Gramnegative bacteria is Escherichia coli.
 58. A method according to claim53, wherein the Gram negative bacteria is Serratia liquefaciens.
 59. Amethod according to claim 53, wherein the Labiatae herb extract isrosemary extract.
 60. A method of extending the color shelf life offresh meat, fish or poultry which comprises applying to or incorporatinginto the fresh meat, fish or poultry a combination of a Labiatae herbextract and a hop extract containing beta acids and packaging the freshmeat, fish or poultry in an atmosphere containing 20% or more oxygen.61. A method according to claim 60, wherein the Labiatae herb extractcontains a Labiatae herb acid selected from the group consisting ofcarnosic acid, carnosol, rosmarinic acid and mixtures thereof.
 62. Amethod according to claim 60, wherein the ratio of beta acids toLabiatae herb acid is between 0.5 and 13.